Insulation thickness Tannoy Gold

I think you’ll have to go by ear, unless you have some fancy test equipment. A lot of vintage Tannoys only had light internal damping applied on top of fine tuned lightly braced cabinets, and then there’s the question of drive unit attachment...

In any case it won’t hurt to read the experiences of a fellow enthusiast, Volker.

http://truefi.blogspot.com/2014/01/a-tannoy-15-enclosure-for-enthusiast_29.html?m=1

pkvintage, contact cement insulation to all the cabinet walls the loosely pack the enclosure avoiding the driver and the port. I'm not sure the cotton capsule stuff will work well. Fiberglass and synthetic fiber wool sticks to itself nicely so it stays in place. If you do not want glass fibers around get the synthetic stuff from Parts express. You fill the cabinet without significantly compressing the fill.